This is a proposal to support the research and writing for a book- Risks Unforeseen: Policy-making, Science and the Politics of Contaminated Blood - that examines the emergence of threats to the global blood supply and the processes that drove policy-making in response to these threats. It will explain the policy decisions that led to many individuals being infected wit HIV and Hepatitis C (HCV) through blood and blood products in Britain. In addition to many recipients of blood transfusions, almost half the hemophiliac population of Britain was infected during the 1980s and 1990's, contracting the illnesses attendant on AIDS and/or HCV. It is a study of how international policy communities and a variety of actors in Britain - government officials, politicians, medical professionals, leaders of voluntary organizations, patients and ther families - perceived the risks of HIV and HCV infection from blood or blood products and understood the emerging scientific knowledge of these viruses. In particular, it explores how those evolving perceptions factored into decision-making with regard to blood donations, blood self-sufficiency, plasma fractionation, heat treatment, the importation of blood products and the compensation of the infected and their families. It also expands the chain of decision-making beyond the national arena, locating national policy-makers within a global environment. It will add to the relatively few empirical studies we have of policy-making with regard to blood safety. It is also a classic study of risk - risk perception, decision-making and management - and should have an impact beyond this particular field. An analysis of how the institutions of law and politics combine with public perceptions and understandings of scientific information to shape a society's decisions on risks worth taking should advance the work of sociologists, political scientists and economists in this field. It draws on uniquely rich data: a press review of the period of HIV and HCV infection; the secondary literature on blood-related health crises in other developed democracies; interviews conducted throughout the 1980s and 1990s and primary documents collected over thirty years. Developments in the ensuing years now allow for a much better understanding of the process of risk management in Britain. The 30-year-rule for government documents has been relaxed and records through 1984 have been released by the National Archives, a 1997 Freedom of Information Act (FOI) provides access to previously closed files, and two recent official inquiries provide discovery material from legal proceedings and a valuable collection of documents from the Department of Health. These data will permit a treatment of the problem of risk management in dynamic terms, as a process that unfolds over time as new types of information are generated, interpreted and fed into new phases of decision-making. It includes a unique perspective by focusing on factors that condition policy-makers' choices about competing interpretations of new scientific evidence in contexts where other pressures impinge on those choices.